Shetty Shravan, Trimbakrao Phad Sharad, Mangal Utkarsh, Patil Suraj, Khader Shah Mohammed Abdul, Ashith M V, Shenoy Satish
Department of Orthodontics and Dentofacial Orthopedics, Manipal College of Dental Sciences Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India.
Departments of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, India.
J Orthod Sci. 2025 Mar 25;14:10. doi: 10.4103/jos.jos_71_24. eCollection 2025.
The present study focused on evaluating and comparing the stresses and displacements generated by various designs of miniscrew-assisted maxillary expansion appliances. The primary focus of this study is on a modified design for treating unilateral maxillary constriction, analyzed using the finite element method (FEM).
Using computed tomography (CT) scans and the modeling software Mimics, a three-dimensional (3D) mesh model of the skull and related maxillary structures was created. First, the necessary material characteristics were determined using FEM. Three models of miniscrew-assisted maxillary expansion appliances were then tested with ANSYS simulation software: (a) a bone-anchored rapid palatal expander (BARPE), (b) a conventional miniscrew-assisted rapid palatal expansion (C-MARPE), and (c) an asymmetric design of a MARPE focusing on unilateral expansion (U-MARPE). The asymmetric U-MARPE design features an attachment connecting the expander to the teeth on only one half of the maxilla. The stress, displacement, and distribution predictions for all three types of expanders were subsequently evaluated via FEM.
Tooth displacement in the U-MARPE (on the expander-to-tooth attachment side) and C-MARPE groups was greater than that in the BARPE group. The stresses on the teeth were lowest in the BARPE and U-MARPE groups (on the expander-to-no-tooth attachment side). C-MARPE exhibited a symmetrical stress distribution around the miniscrew areas. Overall, U-MARPE generated the greatest amount of asymmetric von Mises stress and displacement on the dental landmarks.
This research indicates that, compared to other models, U-MARPE achieves more favorable unilateral expansion effects. The current U-MARPE design can be effectively used to correct unilateral transverse anomalies.
本研究着重评估和比较各种微型螺钉辅助上颌扩弓矫治器设计所产生的应力和位移。本研究的主要重点是一种用于治疗单侧上颌缩窄的改良设计，采用有限元法（FEM）进行分析。
利用计算机断层扫描（CT）扫描和建模软件Mimics创建了颅骨及相关上颌结构的三维（3D）网格模型。首先，使用有限元法确定必要的材料特性。然后用ANSYS模拟软件测试了三种微型螺钉辅助上颌扩弓矫治器模型：（a）骨锚式快速腭中缝扩展器（BARPE），（b）传统微型螺钉辅助快速腭中缝扩展器（C-MARPE），以及（c）一种侧重于单侧扩展的MARPE不对称设计（U-MARPE）。U-MARPE不对称设计的特点是在仅上颌骨的一半上有一个将扩展器与牙齿相连的附件。随后通过有限元法评估了所有三种类型扩展器的应力、位移和分布预测。
U-MARPE组（在扩展器与牙齿连接侧）和C-MARPE组的牙齿位移大于BARPE组。BARPE组和U-MARPE组（在扩展器与无牙连接侧）牙齿上的应力最低。C-MARPE在微型螺钉区域周围呈现对称的应力分布。总体而言，U-MARPE在牙标志点上产生的不对称冯·米塞斯应力和位移量最大。
本研究表明，与其他模型相比，U-MARPE能实现更有利的单侧扩展效果。当前的U-MARPE设计可有效用于纠正单侧横向异常。
